Exposure to environmental hazards may produce a variety of short and long-term effects, including many common chronic diseases. Surprisingly little attention has been paid to identifying associations between environmental exposures and many chronic conditions for which etiologic agents are not yet known. Identification of such associations is a first step towards possible prevention of substantial morbidity in human populations. BRAP's program in environmental epidemiology addresses the role of environmental factors in the etiology of some less well studied chronic diseases. The program is developing methodologies appropriate to the epidemiologic study of chronic diseases which are often difficult to characterize or define precisely, and is adapting methodologies that have been used in studies of cancer for use in studies of nonmalignant diseases. Current emphasis is on identifying risk factors for chronic renal disease which is likely to have a strong environmental component. Chronic renal disease has received little attention in epidemiologic studies, and presents numerous methodologic challenges. A multi-center case-control study of risk factors for chronic renal dysfunction has been completed as has a case-control study of risk factors for biopsy diagnosed IgA nephropathy. Preliminary findings suggest that consumption of certain analgesic medications and environmental exposure to certain solvents and metals may play a role in renal disease etiology. Related ongoing studies involve the development of a renal disease classification scheme for use in etiologic studies, and the analysis of vital statistics and other data to identify time trends, geographic patterns of renal disease, and occupations with potentially increased renal disease risk.